1. Field of the Invention
The present invention relates to a method for controlling rubber products using identification marking, in order to control rubber products molded using a variety of materials, including a plurality of rubber materials such as tires, tubes, belts, hoses, anti-vibration rubber, rubber crawlers, and the like.
2. Description of the Related Art
It is well known that in the manufacturing process for forming rubber products, in particular tires, there are a plurality of processes such as the molding process, the vulcanization process, the visual inspection process, the size selection process, the balance inspection process, and the like, and that there are many types of rubber materials and other materials used. If the effects of a defective material extend to the later processes, then other non-defective materials are wasted, and later processes become extremely complicated, even if the defective material is discovered in the final inspection.
Therefore, it is optimal to discover defective products in the earliest stages by providing an inspection process at the completion of each process. If necessary, it is possible to know the record of the content of the inspection and the results for each process by maintaining a so-called chart for each tire for a certain period.
On the other hand, it is proposed to control the process by applying labels with bar-codes thereon to tires before vulcanization, and integrating the labels into the tires by vulcanization, and by reading this bar-code during the selection of tire size in the inspection process after vulcanization. (For example, refer to Japanese Patent Application Laid-Open (JP-A) No. 61-27711, Japanese Utility Model Application Laid-Open (JP-U) No. 5-90539).
Product control using identification marking by bar-code and the like, as described above, can easily be employed throughout the entire manufacturing process.
On the other hand, after manufactured tires are shipped, they are normally controlled in lots, however, in the case of airplane tires (hereinafter called AP tires), they are controlled individually and are returned to the manufacturer when their period of use has expired. The returned tires are recapped by having their treads replaced and, in some cases, are shipped again as recapped tires. Because of this, in the case of AP tires, it is necessary to maintain a record of the early stages of a manufactured tire.
However, there is no control system, which directly links the record of a tire in the manufacturing stage with the record of the tire after shipping, thus there is the problem that it is difficult, for example, to respond to information or demands from customers adequately and rapidly.